Great work, no doubt. My personal preference is to have annotations because it helps future readers and maintainers understand the code better. Instead of look

Great work, no doubt. My personal preference is to have annotations because it helps future readers and maintainers understand the code better. Instead of looking through the function to see that the variable is in-fact a number, I'd rather just read "@param x {number}". And at that point, one may as well as use closure.